1. Technical Field
The present invention generally relates to a voltage pumping circuit of a Radio Frequency Identification (hereinafter, referred to as “RFID”) device, and more specifically, to a technology of supplying a pumping voltage only when a read or write operation of a memory cell is performed in a memory block of an RFID to reduce current consumption.
2. Description of Related Art
Ferroelectric random access memory (hereinafter, referred to as ‘FeRAM’) devices have attracted considerable attention as next generation memory devices because FeRAMs have a data processing speed as fast as a conventional Dynamic Random Access Memory (hereinafter, referred to as ‘DRAM’), with the added benefit that FeRAM devices can retain data even after the power is no longer supplied to the memory device.
An FeRAM having a structure similar to that of a DRAM includes capacitors made of a ferroelectric substance, having a high residual polarization allowing for data retention after power is no longer supplied to the memory device.
Meanwhile, a general RFID device comprises an analog block, a digital block and a memory block.
The RFID device is operated by a power source which supplies power to the device via a transmission received by an antenna. However, as the distance between the power source and the antenna becomes greater, the received power decreases. As a result, each circuit of the RFID device is required to have relatively low power consumption.
A memory cell requires a pumping voltage only when data are read or written. However, a conventional RFID device supplies the pumping voltage to the memory block continuously when the memory cell does not perform a read or write operation.
That is, the conventional RFID device boosts a power voltage received with the use of a voltage multiplier such as a voltage doubler located in an analog block, and supplies the pumping voltage continuously to the memory block regardless of whether the memory cell is actively writing or reading data. As a result, conventional RFID devices exhibit unnecessary current and power consumption that increases with an oscillation operation of the voltage multiplier.